The illegitimate secret lovechild of Princess Margaret’s husband, Lord Snowdon, has been left out from his £3.2m (AUD $5.4m) will, Daily Mail reports.

Polly Fry was born while Lord Snowdon, high-society photographer Anthony Armstrong-Jones, was on honeymoon with the Queen’s sister in 1960.

His betrayal did not come to light until 2004, when Ms Fry convinced Lord Snowdon to take a DNA test, which subsequently proved he was her biological father.

It is understood she became troubled by persistent rumours that Lord Snowdon – not Jeremy Fry – was her biological father. "When you reach a certain stage in your life, you just want to know…" she once said.

Lord Snowdon at one of his exhibitions in 2002. Image: Getty.
Lord Snowdon died in January this year, aged 86. However, it has been revealed that he shafted his illegitmate lovechild, Ms Fry, from his will completely, despite signing off on the document in 2006, two years after he found out she was his daughter.

According to reports, while he had invited her to call him "Pops", Lord Snowdonmade it clear he did not want it publicly recognised, something said to have troubled Ms Fry.

Lord Snowdon with wife Margaret and their two children. Image: Getty.

Lord Snowdon split from Princess Margaret in 1978 after a reportedly turbulent marriage, plagued by rumours of adultery, drugs and alcohol. He then married Lucy Lindsay-Hogg, with whom he had a daughter, Lady Frances Armstrong-Jones.

However, that marriage also ended when he was caught having an affair with Country Life magazine editor Melanie Cable-Alexander, which led to the birth of his youngest child, Jasper Cable-Alexander.